The majority of photographs taken by amateurs are processed at large film processing centers that can print thousands of photographs per hour. Here, the rolls of film are received, spliced together on large spools, and developed before the individual photographs are printed on a high speed printing machine.
Most high speed photographic printers are programmed to print an area of film that is marked with a notch. To mark the location of each frame on a film, the spools of film are loaded on a frame notching machine that scans the film, determines the position of each frame and places a notch in the correct position. Once the entire spool of film has been notched, the spool is then loaded onto a high speed printer that exposes a continuous web of photographic paper with the area of film marked by the individual notches. After the prints are developed and dried, they are cut into individual photographs and packaged for a customer.
In addition to creating a set of prints from a roll of film, many film processing companies are now offering to provide their customers with an index print. An index print is a single print that contains a small image of each frame on the film. Each image is printed with its corresponding frame number so that a user can quickly view the entire set of prints in order to facilitate ordering copies of selected prints.
Presently, the creation of index prints requires additional equipment and processing steps to be performed by the film developer. Because of variations in the exposure of each frame on the film as well as the different color characteristics of various film types, the printing of the individual frames on the index print had to be carefully monitored in order to produce the best quality picture. This not only increases the cost to produce an index print, but reduces the overall rate at which film can be processed.